Biaxially oriented single and multi-layered bottles may be manufactured from polymer materials such as, for example, polyethylene terephthalate (PET) using a hot preform process, wherein a single or multi-layered preform is heated to its desired orientation temperature and drawn and blown into conformity with a surrounding mold cavity. The preform may be prepared by any conventional process such as, for example, by extruding a preform comprising single or multiple layers of polymer, or by injecting subsequent layers of polymer over a previously injection molded preform. Generally, multiple layers are used for beverage containers, to add diffusion barrier properties not generally found in single layer containers.
The various layers of polymers in the prior art multi-layered containers are generally in intimate contact with one another, thereby facilitating the conduct of thermal energy through the walls of the containers. This allows the chilled contents of the container to quickly warm to the ambient temperature. Accordingly, such containers are often sheathed in, for example, a foamed polystyrene shell to impart thermal insulating properties to the container.
It would be desirable to prepare an improved plastic container which is opaque with unique visual properties without the addition of a coloring agent. Further, it is deemed desirable to impart thermal insulating properties to the improved plastic container. Also, it would be desirable to prepare an improved plastic container having a silvery appearance without requiring the addition of a coloring agent which would adversely effect the recycling characteristics of the container.